Eggs (Easter). Eggs were symbolical from an early time. There was the “Mundane Egg”, in which Brahmâ gestated, with the Hindus the Hiranya-Gharba, and the Mundane Egg of the Egyptians, which proceeds from the mouth of the “unmade and eternal deity”, Kneph, and which is the emblem of generative power. Then the Egg of Babylon, which hatched Ishtar, and was said to have fallen from heaven into the Euphrates. Therefore coloured eggs were used yearly during spring in almost every country, and in Egypt were exchanged as sacred symbols in the spring-time, which was, is, and ever will be, the emblem of birth or rebirth, cosmic and human, celestial and terrestrial. They were hung up in Egyptian temples and are so suspended to this day in Mahometan mosques.

Source: H.P.Blavatsky - The Theosophical Glossary